Is there any app which could generate a lead with required fields in salesforce org when a person likes a page in facebook?
How do I get this done?
Make a small site from site.com in your own salesforce. Go to setup->app setup->develop->sites
You will get a URL from here that will go into the facebook app that you create. The app will diret the person to this site(much like it happens in IBIBO etc) and his/her information is sent to that site. The site's visualForcePage captures this information and converts it into a lead using standard controller...
I hope this helps :)
You'd need to write a tool that connects Facebook API (to check if anyone new liked a post you're interested in) and then use one of the Salesforce APIs to create the SF-data you desire.
Facebook API: https://developers.facebook.com/docs/reference/apis/
Overview of Salesforce API: https://help.salesforce.com/HTViewHelpDoc?id=integrate_what_is_api.htm&language=en_US